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paysages3d/lib_paysages/clouds.c

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#include "clouds.h"
#include <string.h>
#include <math.h>
#include "lighting.h"
#include "shared/types.h"
#include "shared/functions.h"
#include "shared/constants.h"
#include "shared/globals.h"
typedef struct
{
Vector3 start;
Vector3 end;
double length;
} CloudSegment;
static CloudsLayerDefinition NULL_LAYER;
void cloudsInit()
{
NULL_LAYER.noise = noiseCreateGenerator();
NULL_LAYER.coverage = 0.0;
}
void cloudsSave(FILE* f, CloudsDefinition* definition)
{
int i;
CloudsLayerDefinition* layer;
toolsSaveInt(f, definition->nblayers);
for (i = 0; i < definition->nblayers; i++)
{
layer = definition->layers + i;
toolsSaveDouble(f, layer->ycenter);
toolsSaveDouble(f, layer->ymin);
toolsSaveDouble(f, layer->ymax);
noiseSave(layer->noise, f);
colorSave(layer->color, f);
toolsSaveDouble(f, layer->scaling);
toolsSaveDouble(f, layer->coverage);
}
}
void cloudsLoad(FILE* f, CloudsDefinition* definition)
{
int i, n;
CloudsLayerDefinition* layer;
while (definition->nblayers > 0)
{
cloudsDeleteLayer(definition, 0);
}
n = toolsLoadInt(f);
for (i = 0; i < n; i++)
{
layer = definition->layers + cloudsAddLayer(definition);
layer->ycenter = toolsLoadDouble(f);
layer->ymin = toolsLoadDouble(f);
layer->ymax = toolsLoadDouble(f);
noiseLoad(layer->noise, f);
layer->color = colorLoad(f);
layer->scaling = toolsLoadDouble(f);
layer->coverage = toolsLoadDouble(f);
}
}
CloudsDefinition cloudsCreateDefinition()
{
CloudsDefinition result;
result.nblayers = 0;
return result;
}
void cloudsDeleteDefinition(CloudsDefinition* definition)
{
while (definition->nblayers > 0)
{
cloudsDeleteLayer(definition, 0);
}
}
void cloudsCopyDefinition(CloudsDefinition* source, CloudsDefinition* destination)
{
CloudsLayerDefinition* layer;
int i;
while (destination->nblayers > 0)
{
cloudsDeleteLayer(destination, 0);
}
for (i = 0; i < source->nblayers; i++)
{
layer = cloudsGetLayer(destination, cloudsAddLayer(destination));
cloudsLayerCopyDefinition(source->layers + i, layer);
}
}
void cloudsValidateDefinition(CloudsDefinition* definition)
{
int i;
for (i = 0; i < definition->nblayers; i++)
{
cloudsLayerValidateDefinition(&definition->layers[i]);
}
}
CloudsLayerDefinition cloudsLayerCreateDefinition()
{
CloudsLayerDefinition result;
result.color = COLOR_BLACK;
result.coverage = 0.0;
result.noise = noiseCreateGenerator();
result.scaling = 1.0;
result.ymin = 0.0;
result.ycenter = 0.5;
result.ymax = 1.0;
return result;
}
void cloudsLayerDeleteDefinition(CloudsLayerDefinition* definition)
{
noiseDeleteGenerator(definition->noise);
}
void cloudsLayerCopyDefinition(CloudsLayerDefinition* source, CloudsLayerDefinition* destination)
{
NoiseGenerator* noise;
noise = destination->noise;
*destination = *source;
destination->noise = noise;
noiseCopy(source->noise, destination->noise);
}
void cloudsLayerValidateDefinition(CloudsLayerDefinition* definition)
{
if (definition->coverage < 0.5)
{
noiseNormalizeHeight(definition->noise, -1.0, definition->coverage * 2.0, 0);
}
else
{
noiseNormalizeHeight(definition->noise, -(1.0 - definition->coverage) * 2.0, 1.0, 0);
}
}
int cloudsGetLayerCount(CloudsDefinition* definition)
{
return definition->nblayers;
}
CloudsLayerDefinition* cloudsGetLayer(CloudsDefinition* definition, int layer)
{
if (layer >= 0 && layer < definition->nblayers)
{
return definition->layers + layer;
}
else
{
return &NULL_LAYER;
}
}
int cloudsAddLayer(CloudsDefinition* definition)
{
CloudsLayerDefinition* layer;
if (definition->nblayers < CLOUDS_MAX_LAYERS)
{
layer = definition->layers + definition->nblayers;
layer->noise = noiseCreateGenerator();
layer->coverage = 0.0;
return definition->nblayers++;
}
else
{
return -1;
}
}
void cloudsDeleteLayer(CloudsDefinition* definition, int layer)
{
if (layer >= 0 && layer < definition->nblayers)
{
cloudsLayerDeleteDefinition(definition->layers + layer);
if (definition->nblayers > 1 && layer < definition->nblayers - 1)
{
memmove(definition->layers + layer, definition->layers + layer + 1, sizeof(CloudsLayerDefinition) * (definition->nblayers - layer - 1));
}
definition->nblayers--;
}
}
static inline double _getDistanceToBorder(CloudsLayerDefinition* layer, Vector3 position, double detail)
{
double val, min;
if (position.y > layer->ycenter)
{
min = (position.y - layer->ycenter) / (layer->ymax - layer->ycenter);
}
else
{
min = (layer->ycenter - position.y) / (layer->ycenter - layer->ymin);
}
val = noiseGet3DDetail(layer->noise, position.x, position.y, position.z, detail);
return (val - min) * layer->scaling;
}
static inline Vector3 _getNormal(CloudsLayerDefinition* layer, Vector3 position, double detail)
{
Vector3 result = {0.0, 0.0, 0.0};
double val, dval;
val = noiseGet3DDetail(layer->noise, position.x, position.y, position.z, detail);
dval = val - noiseGet3DDetail(layer->noise, position.x + detail, position.y, position.z, detail);
result.x += dval;
dval = val - noiseGet3DDetail(layer->noise, position.x - detail, position.y, position.z, detail);
result.x -= dval;
dval = val - noiseGet3DDetail(layer->noise, position.x, position.y + detail, position.z, detail);
result.y += dval;
dval = val - noiseGet3DDetail(layer->noise, position.x, position.y - detail, position.z, detail);
result.y -= dval;
dval = val - noiseGet3DDetail(layer->noise, position.x, position.y, position.z + detail, detail);
result.z += dval;
dval = val - noiseGet3DDetail(layer->noise, position.x, position.y, position.z - detail, detail);
result.z -= dval;
return v3Normalize(result);
}
/**
* Optimize the search limits in a layer.
*
* @param layer The cloud layer
* @param start Start of the search to optimize
* @param end End of the search to optimize
* @return 0 if the search is useless
*/
static int _optimizeSearchLimits(CloudsLayerDefinition* layer, Vector3* start, Vector3* end)
{
Vector3 diff;
if (start->y > layer->ymax)
{
if (end->y >= layer->ymax)
{
return 0;
}
else
{
diff = v3Sub(*end, *start);
*start = v3Add(*start, v3Scale(diff, (layer->ymax - start->y) / diff.y));
if (end->y < layer->ymin)
{
*end = v3Add(*end, v3Scale(diff, (layer->ymin - end->y) / diff.y));
}
}
}
else if (start->y < layer->ymin)
{
if (end->y <= layer->ymin)
{
return 0;
}
else
{
diff = v3Sub(*end, *start);
*start = v3Add(*start, v3Scale(diff, (layer->ymin - start->y) / diff.y));
if (end->y > layer->ymax)
{
*end = v3Add(*end, v3Scale(diff, (layer->ymax - end->y) / diff.y));
}
}
}
else /* start is inside layer */
{
diff = v3Sub(*end, *start);
if (end->y > layer->ymax)
{
*end = v3Add(*start, v3Scale(diff, (layer->ymax - start->y) / diff.y));
}
else if (end->y < layer->ymin)
{
*end = v3Add(*start, v3Scale(diff, (layer->ymin - start->y) / diff.y));
}
}
/* TODO Limit the search length */
return 1;
}
/**
* Go through the cloud layer to find segments (parts of the lookup that are inside the cloud).
*
* @param definition The cloud layer
* @param renderer The renderer environment
* @param start Start position of the lookup (already optimized)
* @param direction Normalized direction of the lookup
* @param detail Level of noise detail required
* @param max_segments Maximum number of segments to collect
* @param max_inside_length Maximum length to spend inside the cloud
* @param max_total_length Maximum lookup length
* @param inside_length Resulting length inside cloud (sum of all segments length)
* @param total_length Resulting lookup length
* @param out_segments Allocated space to fill found segments
* @return Number of segments found
*/
static int _findSegments(CloudsLayerDefinition* definition, Renderer* renderer, Vector3 start, Vector3 direction, double detail, int max_segments, double max_inside_length, double max_total_length, double* inside_length, double* total_length, CloudSegment* out_segments)
{
int inside, segment_count;
double current_total_length, current_inside_length;
double step_length, segment_length, remaining_length;
double noise_distance, last_noise_distance;
Vector3 walker, step, segment_start;
double render_precision;
if (max_segments <= 0)
{
return 0;
}
render_precision = 3.3 - 0.3 * (double)renderer->render_quality;
segment_count = 0;
current_total_length = 0.0;
current_inside_length = 0.0;
segment_length = 0.0;
walker = start;
noise_distance = _getDistanceToBorder(definition, start, detail) * render_precision;
inside = (noise_distance > 0.0) ? 1 : 0;
step = v3Scale(direction, render_precision);
do
{
walker = v3Add(walker, step);
step_length = v3Norm(step);
last_noise_distance = noise_distance;
noise_distance = _getDistanceToBorder(definition, walker, detail) * render_precision;
current_total_length += step_length;
if (noise_distance > 0.0)
{
if (inside)
{
// inside the cloud
segment_length += step_length;
current_inside_length += step_length;
step = v3Scale(direction, (noise_distance < render_precision) ? render_precision : noise_distance);
}
else
{
// entering the cloud
inside = 1;
segment_length = step_length * noise_distance / (noise_distance - last_noise_distance);
segment_start = v3Add(walker, v3Scale(direction, -segment_length));
current_inside_length += segment_length;
step = v3Scale(direction, render_precision);
}
}
else
{
if (inside)
{
// exiting the cloud
remaining_length = step_length * last_noise_distance / (last_noise_distance - noise_distance);
segment_length += remaining_length;
current_inside_length += remaining_length;
out_segments->start = segment_start;
out_segments->end = v3Add(walker, v3Scale(direction, remaining_length - step_length));
out_segments->length = segment_length;
out_segments++;
if (++segment_count >= max_segments)
{
break;
}
inside = 0;
step = v3Scale(direction, render_precision);
}
else
{
// searching for a cloud
step = v3Scale(direction, (noise_distance > -render_precision) ? render_precision : -noise_distance);
}
}
} while (inside || (walker.y <= definition->ymax + 0.001 && walker.y >= definition->ymin - 0.001 && current_total_length < max_total_length && current_inside_length < max_inside_length));
*total_length = current_total_length;
*inside_length = current_inside_length;
return segment_count;
}
static Color _applyLayerLighting(CloudsLayerDefinition* definition, Renderer* renderer, Vector3 position, Color base, double detail)
{
Vector3 normal;
SurfaceMaterial material;
normal = v3Scale(_getNormal(definition, position, 1.0), 0.25);
normal = v3Add(normal, v3Scale(_getNormal(definition, position, 0.5), 0.25));
normal = v3Add(normal, v3Scale(_getNormal(definition, position, 0.2), 0.25));
normal = v3Add(normal, v3Scale(_getNormal(definition, position, 0.1), 0.25));
normal = v3Scale(v3Normalize(normal), 0.1);
material.base = base;
material.reflection = 0.3;
material.shininess = 2.0;
return renderer->applyLightingToSurface(renderer, position, normal, material);
}
Color cloudsGetLayerColor(CloudsLayerDefinition* definition, Renderer* renderer, Vector3 start, Vector3 end)
{
int i, segment_count;
double max_length, detail, total_length, inside_length;
Vector3 direction;
Color result, col;
CloudSegment segments[20];
if (!_optimizeSearchLimits(definition, &start, &end))
{
return COLOR_TRANSPARENT;
}
direction = v3Sub(end, start);
max_length = v3Norm(direction);
direction = v3Normalize(direction);
result = COLOR_TRANSPARENT;
detail = renderer->getPrecision(renderer, start) / definition->scaling;
segment_count = _findSegments(definition, renderer, start, direction, detail, 20, 60.0, max_length, &inside_length, &total_length, segments);
for (i = 0; i < segment_count; i++)
{
col = _applyLayerLighting(definition, renderer, segments[i].start, definition->color, detail);
col.a = (segments[i].length >= 50.0) ? 1.0 : (segments[i].length / 50.0);
colorMask(&result, &col);
}
result = renderer->applyAtmosphere(renderer, start, result);
return result;
}
Color cloudsGetColor(CloudsDefinition* definition, Renderer* renderer, Vector3 start, Vector3 end)
{
int i;
Color layer_color, result;
if (end.y < start.y)
{
return cloudsGetColor(definition, renderer, end, start);
}
if (definition->nblayers < 1 || end.y - start.y < 0.001)
{
return COLOR_TRANSPARENT;
}
result = COLOR_TRANSPARENT;
for (i = 0; i < definition->nblayers; i++)
{
layer_color = cloudsGetLayerColor(definition->layers + i, renderer, start, end);
if (layer_color.a > 0.0)
{
colorMask(&result, &layer_color);
}
}
return result;
}
Color cloudsLayerFilterLight(CloudsLayerDefinition* definition, Renderer* renderer, Color light, Vector3 location, Vector3 light_location, Vector3 direction_to_light)
{
double inside_depth, total_depth;
CloudSegment segments[20];
_optimizeSearchLimits(definition, &location, &light_location);
_findSegments(definition, renderer, location, direction_to_light, 0.1, 20, 50.0, v3Norm(v3Sub(light_location, location)), &inside_depth, &total_depth, segments);
inside_depth *= 0.02;
if (inside_depth > 1.0)
{
inside_depth = 1.0;
}
light.r = light.r * (1.0 - 0.2 * inside_depth);
light.g = light.g * (1.0 - 0.2 * inside_depth);
light.b = light.b * (1.0 - 0.2 * inside_depth);
return light;
}
Color cloudsFilterLight(CloudsDefinition* definition, Renderer* renderer, Color light, Vector3 location, Vector3 light_location, Vector3 direction_to_light)
{
int i;
for (i = 0; i < definition->nblayers; i++)
{
light = cloudsLayerFilterLight(definition->layers + i, renderer, light, location, light_location, direction_to_light);
}
return light;
}
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